soften wording on absoluteKeywordLocation

it is not strictly true that there will *always* be a fragment in this field:
an error might occur at the schema resource root itself (for example if the
subschema is "false")

Author: karenetheridge

jsonschema-core.xml

@@ -2706,7 +2706,7 @@
                             Note that "absolute" here is in the sense of "absolute filesystem path"
                             (meaning the complete location) rather than the "absolute-URI"
                             terminology from RFC 3986 (meaning with scheme but without fragment).
-                            Keyword absolute locations will always have a fragment in order to
+                            Keyword absolute locations will have a fragment in order to
                             identify the keyword.
                         </cref>
                     </t>